by Calculated Risk on 6/14/2012 10:28:00 AM

Note: there are different measures of "shadow" inventory. CoreLogic tries to add up the number of properties that are seriously delinquent, in the foreclosure process, and already REO (lender Real Estate Owned) that are NOT currently listed for sale. Obviously if a house is listed for sale, it is already included in the "visible supply" and cannot be counted as shadow inventory.

From CoreLogic: CoreLogic® Reports Shadow Inventory Fell in April 2012 to October 2008 Levels

CoreLogic ... reported today that the current residential shadow inventory as of April 2012 fell to 1.5 million units, representing a supply of four months. This was a 14.8 percent drop from April 2011, when shadow inventory stood at 1.8 million units, or a six-months’ supply, which is approximately the same level as the country was experiencing in October 2008.
...
“Since peaking at 2.1 million units in January 2010, the shadow inventory has fallen by 28 percent. The decline in the shadow inventory is a positive development because it removes some of the downward pressure on house prices,” said Mark Fleming, chief economist for CoreLogic. “This is one of the reasons why some markets that were formerly identified as deeply distressed, like Arizona, California and Nevada, are now experiencing price increases.”
...
CoreLogic estimates the current stock of properties in the shadow inventory, also known as pending supply, by calculating the number of distressed properties that are seriously delinquent, in foreclosure and held as real estate owned (REO) by mortgage servicers but not currently listed on multiple listing services (MLSs).
...
Of the 1.5 million properties currently in the shadow inventory, 720,000 units are seriously delinquent, 410,000 are in some stage of foreclosure, and 390,000 are already in REO.

Click on graph for larger image.

This graph from CoreLogic shows the breakdown of "shadow inventory" by category.

Note: The "shadow inventory" could be higher or lower using other numbers and methods; the key is that CoreLogic uses a consistent method (and removes properties currently listed) - and that their estimate of the shadow inventory is declining.